Electron discharge device circuit arrangement



Sept. 13, 1932. R HENTSCHEL 1,877,128

ELECTRON DISCHARGE DEVICE CIRCUIT ARRANGEMENT Filed July 5, 1929 4Sheets-Sheet 1 -OOOOJO0O O 55 INVENTOR. fa m wol Jtc-n l'od-efi,

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A TTORNEY Sept. 13, 1932. E.- R. HENTSCHEL 1,877,128

ELECTRON DISCHARGE. DEVICE CIRCUIT ARRANGEMENT Filed July 5, 1929 4Sheets-Sheet 4 v 5a -46 c 50W 56 Wading "9.5.

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.-1TTORNEY Patented Sept. 13, 1932 own-:0 STATES PATENT OFFICE ERNEST R.HENTSCHEL, OF WASHINGTON, DISTRICT OF COLUMBIA; JOHN OLSON, ADMINISTRATOR OF SAID ERNEST R. HENTSCHEL, DECEASED, ASSIGNOR TO-WIREDRADIO, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE ELECTRONDISCHARGE DEVICE CIRCUIT ARRANGEMENT Application filed July 5, 1929.Serial No. 376,181.

The subject matter of certain arrangements described but not claimed inthe present application is claimed in my copending application SerialNo. 554,345, filed July 31, 1931 which is a division of the presentapplication.

This invention relates broadly to electron discharge device circuitarrangements. More specifically this invention relates to electrondischarge device circuit arrangements in which compensation is providedfor undesirable modulation of oscillations impressed upon the circuitsof an electron discharge device by the unsteady character of the anodecircuit energizing potential.

An object of this invention is to provide an arrangement in which theeffect of the pul sating character of the cathode current supply of anelectron discharge device is caused to neutralize the effect producedupon the out put oscillations of the electron discharge device by thepulsating character of the anode current supply.

Another object of this invention is to pro vide an arrangement in whichthe cathode energizing current of an electron discharge device ismodulated in such a manner that the undesirable modulation by anodecurrent supply of a pulsating character of oscillations impressed uponthe circuits of the electron discharge device or oscillationsdevelopedin the circuits thereof is substantially neutralized.

Still another object of this invention is to provide an arrangementconnected with an electron discharge device in which undesirablemodulation of the output oscillations developed or amplified by theelectron discharge device is neutralized through the countermodulationof the electrical energy supplied to a low potential electrode otherthan the cathode of the electron discharge device.

A further object of this invention is to provi dc an arrangementconnected with an electron discharge device in which undesirablemodulation by anode current of a pulsating character, of theoscillations developed or amplified by the electron discharge device isneutralized by counter-modulating the electrical energy employed forenergizing an electrode other than the anode of the electron dischargedevice, by modulation in 180 degrees phase opposition. with theundesirable modulation through the action of a coupling circuit arrangedbetween the anode circuit and the electrode upon the circuit of whichthe counter-modulated energy is impressed.

A still further object of this invention is to provide an arrangement inwhich the effect of undesirable modulation of the output oscillations ofan electron discharge device caused by the pulsating character ofelectrical energy employed for energizing the circuits of an electrodeof the electron discharge device is neutralized by causing theundesirable modulations to modulate the electrical energy employed forenergizing the circuits of another electrode of the electron dischargedevice'in 180 degree phase opposition with the undesirable modulations.

Other objects and features of this invention will be apparent to thoseskilled in the art to Which this invention relates from the followingspecification and the appended claims.

According to this invention the modulating effect of the pulsations of asource of anode current supply upon the output oscillations of anelectron discharge device'is substantially neutralized by introducing amodulated current upon one of the other electrodes of the electrondischarge device. In this invention an arrangement is provided wherebythe time phase relation between the pulsations of the anode source ofcurrent supply and the modulations of the modulated current impressedupon the other electrode may be varied so that the neutraliza-- tion ofthe undesirable modulations may be properly adjusted. v

In the drawings, Figure 1 illustrates an embodiment of this invention;Figs; 2, 3. 4, 5. 6 and 7 are graphs illustrating principles ofoperation of this invention: Figs. 8. 9 and 10 show modifications ofthis invention in which auxiliary grid electrode electron dis- 3 chargedevices are employed and Fig. 11 illustrates a further modification ofthis in- Vention.

Reference numeral 1 of Fig. 1 of the drawings, designates an electrondischarge device having an anode 1a, a grid electrode 1?) and a cathode10. A condenser 2 is connected to the grid electrode 1?; for couplingthe grid electrode 1?) to the output circuit of another electrondischarge device in cases where the electron discharge device 1 isemployed as an amplifying device.

If it is desired a tuned circuit may be connected between the gridelectrode lb and a convenient point of the cathode circuit and thedevice 1 may be employed as a generator of high frequency oscillations.The device 1 is not, however, limited in its use to that of an amplifieror oscillation generator but may be used also as a repeater valve ordetector.

A choke coil or impedance element 3 is connected to the contactor 1 onpotentiome ter 5 for impressing a biasing potential upon the gridelectrode 16. The potentiometer 5 has a portion thereof shunted acrossthe cathode 10. High frequency oscillation bypass condenser 6 isconnected across the cathode. Another by-pass condenser 7 is pro videdacross the adjustable tap 4. The anode 1a is connected to the outputcircuit 9 which may be of any of the conventional types and may consistof the primary of an audio frequency transformer in cases where thesystem herein described is employed in conjunction with the audiofrequency amplifier of a signal receiving system or a wire relay system,or it may consist of the primary of a tuned or untuned radio frequencytransformer. High frequency oscillation by-pass condenser 8 is providedbetween the low potential end of the output circuit and the cathode 10.Where the system of this invention is employed in conjunction withelectron discharge devices operating at low frequencies the bypasscondensers 6. 7 and 8 will be of course larger in value than where thesystem is employed at high frequencies It will be observed that a sourceof potential is provided in the grid bias circuit in series with tapconnection 4 and impedance element 3. whereby a. predetermined potentialin com bination with the variable potential secured by movement ofcontactor 4 may be obtained on the grid 16.

A filter system 10 which may consist of any suit-able combination ofinductance and capacity units is connected into the circuit of thecathode source of current supply. The filter system 10 is connected tothe output circuit of the rectifier system which comprises the rectifiertubes 11 and 12 and transformer 13. The rectifier tubes 11 and 12 may beof the hot cathode gaseous arc type or any approved type suitable forrectifying a low voltage alternating current. The transformer 13 ispreferably of the type having two secondary windings 13a and 13b and aprimary wind ing 130. The anodes of the tubes 11 and 12 are connected tothe terminals of the secondary 13a and the cathodes are connectedtogether across the secondary winding 13b. The electrical centers of thesecondary windings 13a and 135 are connected to the input terminals ofthe electrical filter 10.

The anode source of current supply for the electron discharge device 1comprises a filter 14:, which is made up of a choke coil 15 andcondensers 16 and 17. A high frequency choke coil 18 is connected intothe circuit of the anode current source of supply between the filter letand the output circuit 9 to prevent high frequency currents of largemagnitude from flowing through the circuits of the filter 14. The anodesof a pair of rectifier tubes 19 and 20 are connected to the terminals ofthe secondary winding 24 of the transformer 21. \Vhere it is moreconvenient, asingle rectifier tube which is either of the vacuum or gascontent type and which employs a pair of anode electrodes may be usedinstead of two rectifier tubes.

A secondary winding 23 is provided to the transformer 21 for sumalyingthe cathode heating current for the rectifier tubes. The primarywindings 130 and 25 of the transformers 13 and 21. respectively, areconnected to the source of alternating current supply 27. A phaseshifting device 26 is connected into the primary circuit of thetransformer 13 whereby the phase of the secondary current of transformer13 may be shifted with respect to the phase of the secondary current ofthe transformer 21. at will. The secondary windings 13a and 13?) oftransformer 13 and the secondary windings 23 and 24 of transformer 21may be mounted upon one core where it is desirable to combine the twotransformers 13 and 21. In case all of the secondary windings 130, 137).23 and 24 are wound upon a single core the phase shifting deivoe 26 mustbe connected into the circuit of the secondary 13a.

The operation of the arrangement illustrated in Fig. 1 is as follows:

The alternating current from the source 27 is transmitted through thephase shifting device 26 to the transformer 13 in which the voltage isstepped up or down to a certain value. The output of the secondarywinding 13a is rectified through the action of the ull wave rectifiersystem employing rectifier tubes 11 and 12. The rectified potentialimpressed upon the input circuit of the filter 10 from the output of therectifier system is of a pu sating nature of a wave form simiar to thatillustrated by Fig. 2 of the drawings. The output of the rectifiersystem is partially filtered through the operation of the filter system10. The wave form of the potential supplied to the cathode 1c from theout u of the filter 10 is illustrated in Fig. 3 of the drawings. Anegative biasing poential of a pulsating character. such as illustratedin Fig. 4 of the drawings, is impressed upon the grid electrode 1?) dueto voltage drop in potentiometer 5. It will be noted that this gridbiasing potential is 180 degrees out of phase with the potential wavedelivered by filter 10, that is, the maximum negative value of the gridbias occurs at the same instant as the maximum positive value of thefilament current. The connection l between the potentiometer 5 and thesource of grid biasing potential is adjusted as explained below so thatwhen the current through the cathode 10 is maximum the numericalmagnitude of the negative biasing potential on the grid electrode 1?)increases because of the pulsating character of the cathode current. Ths increase in the negative biasing potential applied to the gridelectrode 1?) tends to reduce the anode current flowing through theelectron discharge device 1 and compensate for the increase in cathodeenergization caused by the pulsating character of the cathode energizingcurrent.

With the connections as shown in Fig. 1, the right terminal ofpotentiometer 5 is positive and the left terminal is negative. Since themidpoint of the cathode is at zero potential, the point of thepotentiometer is also at zero potential midway between the two cathodeconnections. If the grid return 4 is connected to the point of thepotentiometer 5 midway between the cathode connections, the potentialapplied to the grid will be due only to source 65. If the grid return 4is connected to the left of this midpoint of the potentiometer, asshown, the voltage drop from this midpoint to the grid return connectionwill apply to the grid a voltage negative with ref erence to themidpoint of the cathode, and will include pulsations or ripples presentin the current supplied to potentiometer 5 from the filter 10. Thefarther the return connection 4 is connected to the left of themidpoint, the more ripple it will pick up. The negative voltage dropfrom the midpoint of the potentiometer 5 to the return connection' l isadded to the negative voltage supplied by source 65. At the instant whenthe pulsations of the voltage impressed on potent ometer 5 have theirpeak, the current flowing through potentiometer 5 has its peak and thenegative grid bias voltage has its peak. Therefore at the instant whenthe pulsating voltage impressed on the cathode has its peak and tends tocause a maximum instantaneous Value of anode current, the pulsatingnegative grid bias voltage has its negative peak and tends to cause aminimum instantaneous value of anode current, so that the two effectsoppose each other. The grid return connection 4 on potentiometer 5 canbe adjusted so that the effects on the ode current will be equal and,opposite. and the anode current will then be without pulsations due tothe source of cathode potential. The source 65 can then be adjusted tothe proper value of continuous current operating potential.

The position of the variable filament tap on potentiometer 5 depends onthe value of potential required to be impressed across the filamentterminals in operation.

The anode current of the electron discharge device 1 is supplied fromthe source of alternating current 27 through the operation of thetransformer 21, the rectifier system which includes the rectifier tubes19 and 20 and the filter 14. The anode current is also pulsating incharacter. When the cathode 1c of the electron discharge device 1 isenergized by a steady current and the anode circuit of the device 1 issupplied with partially filtered rectified alternating current it hasbeen found that the wave form of the anode current is of the typeillustrated. in Fig. 5.

Under the conditions of operation in which a steady source of anodecurrent supply and the grid electrode biasing potential arrangement suchas illustrated in Fig. 1 are employed, the wave form of the anodecurrent of device 1 will he of a form such is illus trated in Fig. 6.When the anode is supplied with pulsating voltage from rectifier 19-20,it is necessary to make further adjustments to secure anode current freefrom pulsations.

By properly adjusting the phase shifting device 26 so that the phaserelations between the maxima of the cathode energizing current and themaxima of the anode current are in phase and by properly adjusting thevariable connections of the potentiometer 5 so that the maxima of thecathode current are in 180 degree phase opposition with respect to themaxima of the grid electrode biasing potential and the maxima of thegrid bias potential and so that the magnitude of the pulsationsimpressed on. the grid are of proper magnitude, are in 180 degree phaseopposition with respect to the anode potential, the pulsating characterof the anode current is eliminated and the anode current is caused toassume a steady character as illustrated in Fig. 7, which is a curve ofsubstantially the same character as is obtained by adding the curves ofFigs. 5 and 6.

Fig. 8 of the drawingsillustrates a modified form of this inventionemploying an electron discharge device having an auxiliary or shieldgrid electrode which is energized by a pulsating direct current forneutralizing the effect of a pulsating anode potential. A couplingcondenser 31 is connected together with the choke coil 30 to the gridelectrode 29?; of the electron discharge device. A source of gridelectrode biasing potential 32 is connected to the choke coil 30 and anadjustable connection of the potentiometer 36.

A source of current supply 33 is connected to the cathode 290. Thesource 33 may be a steady or pulsating direct current source or it maybe an alternating current source. The negative terminal of the source ofdirect current supply 34 is connected to theca-thode circuit and thepositive terminal is connected to the auxiliary grid electrode 29d,through alternator 35.

An alternating potential of relatively small magnitude is impressed uponthe circuit of the auxiliary grid electrode 29d by the source 35. Theffect of superimposing an alternating potential upon the potential ofthe source. 34 which is a direct current generator is such that apulsating potential will be impressed upon the auxiliary grid electrode294. The phase and amplitude of the alternating potential supplied bythe source 35 may be varied by any convenient means so that the maximaof the potential applied to the auxiliary grid electrode occur at theproper time with respect to the maxima of the cathode current. the anodecurrent and the grid electrode biasing potential. The sources 34 and 35may be combined into one, where a direct current generator is employedas the source 34, since the proper pulsating character may be impartedto the supply derived from a direct. current generator by regulating thecommutation. High frequency by-pass condenser 37 is connected across thesource of grid electrode biasing potential for reducing any hi hfrequency potential that may have a tendency to develop across thesource 32 to a low value. Another by-pass condenser 38 is connectedacross the terminals of the cathode 29c. Condenser 39 is connectedbetween the auxiliary grid electrode 29d and the cathode 290. The highfrequency circuit between the output circuit 41 and the anode iscompleted through the condenser 40. A rectified alternating currentsource of anode current supply similar to the anode current supplyillustrated in Fig. 1 is provided for the electron discharge device 29.

In Fig. 9 of the drawings an embodiment of this invention in which thealternating component of the pulsating anode current supply is impressedupon the circuits of the auxiliary grid electrode 42d of the electrondischarge device 42 through the operation of the transformer 43 theprimary winding of which is connected in series with the current supplyof the anode 42a. The coupling between the secondary winding of thetransformer 43 and the primary winding may be varied so that theamplitude of the secondary potential as well as its phase relation maybe varied. A phase shifting device 44 is connected to the secondary oftransformer 43 and the resistance unit 45 which serves as a couplingmeans for conveniently impressing the alternating current obtained fromthe trans former upon the circuit of the direct current source 46. Thephase relation between the maxima of the pulsating potential applied tothe auxiliary grid electrode is adjusted with respect to the phase ofthe maXima of the pulsating potential applied to the other electrodes bythe phase shifting device 44 or by varying the coupling of thetransformer 43. lVhere complete neutralization of the modulating effectof the pulsating anode current cannot be obtained by varying thecoupling of the transformer 43 and the phase shifting device 44, theposition of the adjustable contacts associated with the potentiometer 47may be varied so that the phase relation between the maxima of the gridbiasing potential and the maxima of the cathode current may be properlyadjusted.

In Fig. 10 another modification of this invention similar to themodification illustrated in Fig. 9 is shown. The electron dischargedevice 48 is provided with an anode 48a, a grid electrode 485, a cathode48c and an auxiliary grid electrode 48d. The circuits of the cathode 48cand the grid electrode 48?) are energized in a manner similar to that inwhich the circuits of the cathode and grid electrode of the electrondischarge device 29 illustrated in Fig. 8 are energized. A voltagedivider 52 which may be in the form of a resistance unit or a choke coilto which connection at a multiplicity of places may be made is providedacross the source of anode current supply. A transformer 50 havingprimary and secondary windings between which the coupling may be variedis connected with its primary winding in series with the anode currentsupply of the electron discharge device 48 and its secondary winding tothe coupling device 51 which may be a choke coil or a resistance unit orother form of conductive or inductive coupling. The phase shiftingapparatus 49 is connected into the circuit of the auxiliary electrode4861. A variable connection is provided between the voltage divider 52and the coupling device 51 whereby a variable positive potential whichis equal to a fraction of the anode potential may be applied to theauxiliary grid electrode 4861. The phase shifting apparatus 49 isemployed in conjunction with the variable coupling transformer 50 andthe potentiometer 53 to provide means whereby the proper phase relationbetween the maxima. of the anode current, the cathode current, the gridelectrode potential and the auxiliary electrode potential may bemaintained. Current supply sources 54 and 55 which are of the same typeas are employed in the form of this invention illustrated. in Fig. 8 areassociated with the circuits of the grid electrode and the cathoderespectively.

A modified form of this invention in which a transformer 56. havingprovision for adjustin the coupling between the primary and secondary,employed to impress an alternating potential upon the cathode circuit ofthe electron discharge device 51' from the source of pulsating anodepotential, is illustrated in Fig. 11 of the drawings. Phase shiftingapparatus 58 similar to the apparatus 49 of Fig. 10 is connected to thesecondary of the transformer 56 and to the coupling device 59, which maybe in the form of a transformer, choke coil or resistance. Apotentiometer 60 is connected across the cathode of the device 57Current supply sources 61. and G2 are COIHIQCt-GQ into the cathode andgrid electrode circuits, respectively, oi the device 57. In operatingthe pat sating anode current is caused to energize the transformer 56and induce an alternating electromotive force into the secondarythereof. An alternating current is caused to flow in the circuit of thesecondary of the trans former 56, the phase adjusting apparatus 58 andthe coupling device 59. r he current flowing in the cathode circuit ofthe device 57 is varied in accordance with the alternating currentcomponent flowing in the circuit including the phase shifting apparatus58. By adjusting the coupling of the transformer 56, the phase shiftingapparatus 58 and the potentiometer 60 so that the maxima of the anodecurrent, the cathode current and the grid electrode biasing potentialare in cor-- rect phase relation, the modulating effect of the pulsatingcharacter of the anode potential may be neutralized.

While I have described my invention in several of its preferredembodiments it is understood that various modifications thereof may bemade without departing from the scope and spirit of this invention andthat therefore I do not desire to limit this invention to the exactdetails set forth in the foregoing specification, except in so far asthese details may be defined by the appended claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is as follows:

1. In a power supply system for electron tubes, an electron tube havinga cathode, anode, grid and shielding grid, a source of pulsating directcurrent for energizing said anode, a source of pulsating direct currentfor energizing said shielding grid, and a current source for energizingsaid cathode, said source for energizing said shielding grid beingconnected to said shielding grid and to the circuit of said cathode, thepulsations applied to said shielding grid being of magnitude and phasefor neutralizing in the circuit of said anode the pulsations of thepotential directly applied by said source for energizing said anode,whereby a smooth continuous anode current is produced.

2. In a power supply system for electron tubes, an electron tube havinga cathode, anode, grid and shielding grid, a source of pulsating directcurrent for energizing said anode, a current source for energizing saidcathode, a source for energizing said shielding grid, an anode circuitconnecting said anode to said source for energizing said anode, ashielding grid circuit connecting said shielding grid to the circuit ofsaid cathode through said source for energizing said shielding grid, acoupling circuit coupled to said anode circuit and to said shieldinggrid circuit for impressing pulsations in said anode circuit upon saidshielding grid circuit, and phase adjusting means for varying the phaseof the pulsations impressed upon said shielding grid in desiredrelation, whereby the effect upon the current in said anode circuit ofthe pulsations impressed upon said shielding grid neutralizes thepulsations in potential directly impressed upon said anode from saidsource for energizing said anode and a smooth continuous anode currentis produced.

ERNEST R. HENTSCHEL.

DISCLAIMER 1,87 7,128.-Emest R. Hentschel, Washington, D. C. ELECTRONDISCHARGE DEVICE CIRCUIT ARRANGEMENT. Patent dated September 13, 1932.Disclaimer filed September 6, 1934, by the assignee, Wired Radio, Inc.

Hereby enters this disclaimer to that part of the claims in saidspecification which are designated as claims 1 and 2 of said patent.

[Oficial Gazette October 2, 1934.]

DISCLAIMER 1,877,128.Ernest R. Hentschel, Washington, D. O. ELECTRONDISCHARGE DEVICE CIRCUIT ARRANGEMENT. Patent dated September 13, 1932.Disclaimer filed September 6, 1934, by the assignee, Wired Radio, Inc.Hereby enters this disclaimer to that part of the claims in saidspecification which are designated as claims 1 and 2 of said patent.

[Ofiicz'al Gazette October 2, 1934.]

